PURPOSE : A system for providing real estate/auction information using telephone number information and a method therefor are provided to add information about a corresponding object associated with an owner to a real estate or an auction object and offer information to an information customer through a telephone line.CONSTITUTION : An information providing server(214) connects to wired telephone networks(202, 204, 205) and mobile phone networks and provides information of a corresponding telephone when one telephone requests information about the corresponding telephone among a plurality of wired telephones(200, 208) or mobile phones(201, 207). A telephone information DB(211) connects to the information providing server(214) for providing owner and position information about each telephone number. An auction information DB(213) connects to the information providing server(214) for providing information about an auction object through a telephone number. A real estate information DB(212) connects to the information providing server(214) for providing information about the buying and selling of a real estate through a telephone number. A voice synthesizing system(210) converts information provided from the auction information DB(213) and the real estate information DB(212) into a voice signal. An ARS(Automatic Response Service) system(209) provides information requested from the one telephone to the information providing server(214).? KIPO 2003